Photographic objective lens of high speed with wide field of view



SEARCH ROOM Oct. 11, 1960 A. w. TRON PHOTOGRAPHIC OBJECTIVE L 2,955,513OF HIGH SPEED 1 w '7' 2 0 3 g WITH WIDE FIELD 0 Filed April 17.

|NVENT OR Albrecht Wilhelm Tronmer ATTORNEYS United States PatentPHOTOGRAPHIC OBJECTIVE LENS OF HIGH SPEED WITH WIDE FIELD OF VIEWAlbrecht Wilhelm Tronnier, New York, N.Y., assignor to Farrand OpticalCo., Inc., New York, N.Y., a corporation of New York Filed Apr. 17,1958, Ser. No. 728,960

9 Claims. (Cl. 88-57) The present invention relates to high speedphotographic objectives whose relative aperture lies betweenapproximately 1:1.7 and 1:2.4 and whose useful field angle (20: amountsto from 56 to 66.

Attempts have already" been made to produce photographic objectiveshaving both high speed and wide field of view. In these proposedconstructions, however, either the field was flattened over aninsufficient angle, or they were required to be used with supplementaryfield lenses (the field flattening lenses of Smith) in order to achievean anastigmatically flattened field. In applicants copending applicationSerial No. 729,144, filed Apr. 17, 1958, applicant has disclosed theconstruction of objectives which, without recourse to supplemental fieldflattening lenses, possess an anastigmatically flattened field togetherwith high relative aperture for a wide field of view.

The objectives of applicants copending application above referred toachieve a substantial improvement over the art prior thereto in thatthey are capable of imaging sharply a wide angle field of view even atmaximum aperture and hence with the large ray bundle cross-sectionswhich are a concomitant of their high relative aperture. The presentinvention provides an improvement on the objectives in the copendingapplication above referred to in that, in addition to a furtherimprovement in imaging properties within the wide field of view, theyachieve relatively long intersection distances or back focal lengths onthe image side of the system between the objective and the image plane.Whereas the objectives of the copending application above referred topossess on the image side intersection distances of less than 75% of theequivalent focal length of the system, those of the present inventionpossess such intersection distances exceeding 80% of the equivalentfocal length.

Accordingly the objectives of the present invention may be successfullyused in mirror reflex type cameras. The increase in intersectiondistances achieved facilitates the provision of the necessary clearancebetween the rear elementof the objective and the movable mirrormechanism. The increase in intersection distances achieved by thepresent invention is not obtained at the cost of a diminished lensperformance such as customarily results from a decrease in the ratio offocal length to intersection distance. Hitherto, increases have beenachieved in rear intersection distances in so-called normal objectiveshaving a convergent rear assembly behind the diaphragm position, andconversely reduction has been achieved in the intersection distances oftelephoto objectives with divergent rear assemblies, by increasing therefractive powers of certain elements of such lenses. This has either increased the zonal errors or has reduced the useful field angle or therelative aperture. 7

According to the present invention instead there is provided anobjective lens system including a front assembly having its most sharplydivergent surface adjacent the diaphragm position and a rear assembly ofGaussian ice 5 phragm position lying between 0.8 and 1.8 times theequivalent focal length of the system. This first component is moreoverdisposed with a strongly divergent concave surface directed toward thediaphragm. The vertex of the rear surface of the firstcomponent isspaced from the second component by a distance of from onethird totwo-thirds of the equivalent focal length of the system. The secondcomponent takes the form of a doublet having unequal exterior surfacecurvatures. The elements of this doublet are of opposite power sign butpossess together a positive total power. Behind the sec- I ond componentthere is disposed a meniscus-shaped convergent third component havingits concave surface presented to the diaphragm. The front assembly iscompleted by means of a doublet of negative power and meniscus shapeadjacent the diaphragm position, the concave exterior surface of thisfourth component being turned toward the diaphragm. The convergent thirdcomponent is so enclosed by the second and fourth components that theair spaces between the second and third and between the third and fourthcomponents possess the shape of negative lenses having their morestrongly curved concave surfaces presented to the diaphragm.Consequently both of these air spaces act as positive air lenses.

The invention will now be described by reference to the accompanyingdrawings in which Figs. 1 and 2 are axial sections through two lensesaccording to the invention.

Referring to Figs. 1 and 2, the lens of the invention includes sixcomponents I to VI, numbered from the long toward the short conjugateend of the system. Components I to IV make up the front assembly, andcomponents V and VI make up the rear assembly. Component II includesfront and rear elements L and L component IV includes front and rearelements L and L and component V includes front and rear elements L andL The other components I, III and VI include respectively one element LL and L each. In the embodiments illustrated therefore the lens of theinvention includes nine elements.

The radii of curvature of the front surfaces of the elements areidentified by the letter R with arabic subscripts corresponding to theRoman identification of those elements above discussed, and the radii ofcurvature of the rear surfaces of the elements are identified by thesymbol R with similar subscripts. The axial thicknesses of thecomponents are identified by the letter d with subscripts which identifythe elements respectively, and the axial spacings of the elements areidentified by the letter s with double surscripts identifying theelements preceding and following such spacings. The diaphragm positionis indicated by division of the spacing a into portions b and bpreceding and following the diaphragm.

According to the present invention the disadvantages of the prior artlenses above adverted to are obviated by providing on the long conjugateside of the system, in front of the diaphragm position, a front assemblyor combination of components having its most strongly divergent concavesurface presented to the diaphragm space whereas the plural element rearassembly behind the diaphragm position is of Gaussian type. The firstcomponent I in the front assembly is of negative power, is provided withunequal surface curvatures, and is advantageously of meniscus shape. Itis spaced at a distance A from the diaphragm position lying between 0.8and 1.8 times the equivalent focal length f of the system. The componentI is disposed with a strongly divergent concave rear surface directedtoward the diaphragm. The vertex of this rear surface of element I isspaced from the next component II by a distance s of from one-third totwo-thirds of the equivalent focal length f. Component II forms adoublet having unequal exterior surface curvatures. The elements L and Lof this doublet are of opposite power sign but possess together apositive total power. Behind component II there is disposed ameniscus-shaped convergent component HI having its concave surfacepresented to the diaphragm. The front assembly is completed by means ofa doublet IV of negative power and meniscus shape adjacent the diaphragmposition, the concave rear exterior surface of component IV being turnedtoward the diaphragm. The convergent meniscus component III is soenclosed by the components II and IV that the air spaces betweencomponents II and III and between components III and IV possess theshape of negative lenses having their more curvatures, to doublets andto meniscus-shaped lenses,

the general plan of the lens may be symbolically written as follows:

U; +D; j-M; D; diaphragm; Gaussian rear assembly If, as in the preferredconstruction, the front component I is of meniscus shape this symbolicalnotation takes on the following form:

M; +D; +M; D; diaphragm; Gaussian rear assembly According to a furtherfeature of the invention the lenses thereof are characterized by adistribution of powers among the components I to IV thereof as set forthin the following table, in which f represents the equivalent power ofthe complete objective and 4m, (#111, 95 refer respectively to the sumsof the powers of the exterior surfaces of the components I, II, III andIV:

As previously stated, this power distribution is employed in conjunctionwith a spacing of the component I from the diaphragm position amountingof from 0.8 to 1.8 times the equivalent focal length 1 and inconjunction with a spacing of the components I and H of from onethird totwo-thirds of the equivalent focal length 3.

For the components V and VI of the rear assembly power distributions canbe employed of the type usual in Gaussian systems, within the followinglimits:

The alternating succession of power signs of the components exemplifiedin the succession of a negative meniscus (I), a positive doublet (II)and the succession positive meniscus (III) and negative doublet (IV),and the provision of two doublets in the front assembly make possiblethe distribution of powers thus set forth.

From the data on power distribution which has been given it is apparentthat the objectives of the invention are characterized by extremely lowpowers for the individual components thereof. This makes possible in astrikingly simplified manner the achievement over a wide field of animage with low zonal errors even with the very large cross-sectionswhich characterize the axial and extra-axial ray bundles in high speedobjectives when operated at full aperture.

According to a further feature of the invention, the zonal departures ofthe meridional coma are held to very low values even for lateral bundlesof high angular inclination to the system axis by attribution ofappropriate powers to the air lenses between components II and III andbetween components III and IV. The air spaces between these pairs ofcomponents, identified in the drawing by the notations s and s possesssuch powers that the sum of the surface powers of the adjacent surfacesof components II and III lies between .55 and 1.5 times the equivalentpower of the entire system, and likewise for the sum of the powers ofthe adjacent surfaces of components HI and IV. Referring to these powersums as the powers of the air lenses between components II, III andbetween components III and IV and identifying them as 41 and s,respectively, these relations may be algebraically written as follows:

In the foregoing relations and throughout the present application Iindicates the equivalent total power of the objective. The symbolindicates a surface power or a surface power sum, according to thenature of the subscript applied to it. If the subscript identifies asingle surface, with such subscript indicates the power of such surface.If the subscript indentifies a single lens element, the symbol p withsuch subscript indicates the sum of the powers of the surfaces of suchelement. If the subscript identifies a component including more than oneelement, the symbol with such subscript indicates the sum of the powersof the exterior surfaces of such component. The power of a singlesurface is, as usual, given by the ratio of the difference in indicesacross the refracting surface to the radius of curvature thereof thus:

is identified as t whereas the power of the rear surface is identifiedas The sum of the surface powers of the element 5 is accordinglyCorrespondingly, the power of an air lens enclosed between twocomponents z and z+1 whose vertices are separated by a spacing s isgiven as the sum of the powers of the surfaces limiting this air lens,thus:

In the accompanying drawings two embodiments of the lens of theinvention are shown in axial section.

There will now be given data on three examples of lenses according tothe invention. The lenses of these examples possess in accordance withthe object and achievement of the invention a true anastigmatic fieldflattening, achieved without supplemental field flattening lenses and bythe use of commercially available glass types.

For each example there is given the equivalent focal length 1 of thesystem, the last intersection distance p' on the image side of thesystem (for an infinitely distant object) and also the useful relativeaperture, and the field angle Zw on the object side of the system.

The first lens to be considered, which will be referred to as Example 1,is of relative aperture 1:2.0 and of field angle 2w =60. It ischaracterized by a distribution of powers among the six componentsthereof as set forth in the accompanying Table 1, by a spacing A ofcomponent I from the diaphragm position amounting to 1.25 f, and by aspacing of components I and II amounting to 0.5 f.

TABLE 1 The power distribution of Table 1 may be restated to the nexthigher order of accuracy in terms of the accompanying Table 2:

In the lens of Example 1 the powers of the doublet components H, IV andV as given in Table 2 are obtained b TABLE 4-Continued L1 and Ln Of f-For the lens of Example 1 the following glasses may used:

by means of powers for their individual elements as set TABLE 5 forth inthe accompanying Table 3:

Eight lill'iosplhate crown n-lgg QB P8618 311 81111111 crown- 7l= T LE 3gght blariu tln flint n=lg7 68" ii a um 1 m=+ Nmht'aiiim .f?f? 2:1.60m=-O 9IQ Normal dense crown. n=1.61 1 02!} Normal flint n=l.60 IVa''Dense barium crown n=1.59 +0j0q Heavy lanthanum crown n-1.71

=-2.02q The foregoing disposition of component, element, and

individual surface'powers leads with the glasses of Table 1 The powerdistribution among components and ele- 5 and with the introduction ofappropriate element spacments set forth in Tables 2 and 3 for the lensof Examings to the following lens formulation for the lens of ple 1 isthe product of a distribution of individual sur- Example 1, in whichlinear dimensions are given in mulface powers as follows: tiples of theequivalent focal length f of the system.

TABLE 6 Thickness 11 Index of Abbe Component Element Radil and Spacing:Refraction Number R; =+L7f I LI ti =0.14f 7L1 =1.50 v =67 sm =0.48f Rh=+1.2 I Lu. d2. =0.28 f m.=1.69 m=54 R' .=0,8f II :-.zb=0f Rab =-0.8f 7L111: dis =0.03f mb=1.57 vib=51 R2b=+2.9f R +0 7! 82.3 =0.01f 3 III Lind: =0.07f m =1.71 1 =54 R's =+1.3f

83,4 =0.01f R4, =+0.43 I L v. d4, =0.03f Tit-=11) vh=38 Rl;=+0.25f IV84..4s=0f Rib =+0.25 Lrvb dis =0.10] mb==L6l Wb=5 34.5 =0.l9f bl =0.13/Rss =0.60 Lv. d5. =0.04f n .=1.60 III-=38 R' ,=+0.60f V flsmb=0f Ra,=+0.60 f LVb (in, =0.l2f nu,=1.59 vsb=61 8M =0.01f Ru '=+3.3f VI Lvr do=0.09f no =1.71 v5 =34 R's =--1.5f

TABLE 4 In the lens whose data are given in Table 6, the inter- +0 304,7 section distance p' on the image side of the system. is

1: 0 0 82 f 'n e I I n e aao a e ,wiei incues e ir orer Thdt fTbl6 hltld ththd d aa=+ Seidel corrections, can be further corrected to thefolaa=+ lowing form for an ob ective of mm. equivalent =-0.71'I focallength, relative aperture f/2.0, useful field 2w =62, =0.20{ 7 and imageside intersection distance p' =83.333 mm.;

TABLE 7 Component Element Radtl, mm. Thlcknessd and Index of Re- AbbeSpaeing|,mm. tractionn Number,

v R =+168.6263 I...-- III at 14-3006 fll -1.5038 n -66.7

1.: -47.6686 R1. -+l19. 3879 L d1. =27.6764 nil-1.6935 was-53.5

R'1|--80- 0832 n il-211 Rn, -80.0832 L1 tin, =3.8135 M -1.5704 tab-51.0

REP-+285. 1391 am -0.4767 R; -+71.3269 m L d1 =6-6736 7): 1- 7130 n 53.9

01.1 -0.4767 R1. -+42. 6927 L d4. =3-3388 nil-1.6034 Yin-38.0

Elm-+24. 7877 Wu mew-0 Rib =+24. 7877 Lrv (In, -10.0104 nib-1.6127 r-58.6

Blip-+31. 0322 a -18.7814 b 12.7814 Rs. -59. 7606 L dll =3. 8135nu-1.6031 7 38-0 R' =-+59.7606 V 8n.th=0

B -+59.7606 L an, =12. 8938 nib-1.5891 yrs-6L2 em =0. 4767 Re =+328.9132V1 Lv do "8.9617 1 L7130 n=53.9

In this objective the negative meniscus in the front asof the inventioneven with this simplification represents sembly, formed as a doublet,comprises two meniscus shaped elements of opposite power sign.Consequently the alternating succession of power signs is carriedthrough not only for the system components but also for the individuallens elements throughout the front assembly.

In the lenses of the invention, whose make-up may be symbolicallywritten: M +D +M D diaphragm --D +U, the doublets may be provided withthe same radii on the adjacent surfaces of their two elements so thatthis interface may be made a cemented one. This construction may beapplied to all three of the doublet components II, IV and V. While theadoption of this simplification involves sacrifice of the possibilitiesof correction which inhere in the use of difierent radii of curvaturefor such adjacent surfaces, nevertheless the objective a distinctimprovement in the photographic art.

The applicant has found that for certain purposes it is advantageous tomake the front component I or the rear component VI or both of two lenselements. Such a construction does not however depart from the essentialproperties of the lens of the invention.

Example 2 The second example of a lens system according to the inventionfor which data will be given is a lens of relative aperture 1:1.9 havinga field angle of 63, and an image side intersection distance of 82.9% fwherein f is the equivalent focal length of the system. With lineardimensions as multiples of f the data for this system is set forth inthe accompanying Table 8.

TABLE 8 Com- Element Red]! Thickness d and Index of Re- Abbe ponentSpacing s fraction 11 Number r R; -+1. 6703! I In d1 -0.14165f H -1.5038n -66.7

m =0. 412171 In H1826, a 0 214141 1 seas ass I. In "In- "l- Rie -0. 7885I II mas-=0 (cemented) L "(178W a 0 03771] 1 104 1 ns lb ms- .5 vie-6 -0Was-+2. 8244 I am =0.00472f R; =+0.7065f III L!!! is =0. 06610 I 'II; 1.7130 n -533 am =0.00472f Rn +0. 4229] Lxv; d4. =0. 033051 1u-==1.6034v4.==38.0

R'u -H). 2455! IV a1-.4b=0 (cemented) Rlh-+0-2455f Lrvb dis =0.10057fms=1.6127 rib-58.6

Rub-+0. 3074 f au =0. 18604 1 b =0. 13604 f R. =-o. 5919 f Lv. 110.03777! flu-=1. 6031 Yin-38.0

R',.=+o. 5919 f V v =0 (cemented) Rub +0. 5919 f Lvh dsb 0.122761"lb-1.5891 lab-51.2

R'sb -o. 6404;

am -0.00472f v1 L Him! :1. 0 088771 1 me as e W I 1| I '5 R's --l.5289fThe individual surface powers and the element and component power sumsof the lens of Example 2 are set forth in the following Table 9 asmultiples of the equivalent power Q of the entire system:

TABLE 9 du I 0.5242 Q The powers and 5, of the air lenses betweencomponents H and HI and between components III and IV respectively arein the system of Example 2 +0.8073Q and +0.8589Q Example 3 In theExample 3 now to be gievn the power of the divergent meniscus frontcomponent I is, in contrast to the Examples 1 and 2, larger than thepower of the doublet II. In addition the elements of the rear assemblybehind the diaphragm possess somewhat larger powers, and the image sideintersection distance has been increased to over 88% of the equivalentfocal length in order to facilitate use of the lens in reflex typecameras.

In the construction of this Example 3, glasses of extremely high indexhave been avoided, without however any loss in performance. On thecontrary the glasses of the examples already given have been retainedwithout change. The relative aperture of this lens of Example 3 is 1:2and the useful image field amounts to 62 degrees.

The power sums of the components and elements are given in the followingTable 10, as multiples of the equivalent power Q of the system:

This set of power sums is achieved by provision of individual surfacepowers as set out in the following Table 11.

10 TABLE 11 The system of Example 3, with the power distribution givenin Tables 10 and 11, is obtained with a set of radii, thicknesses andspacings, and for glasses of indices as set forth in the following Table12, wherein linear dimensions are given in multiples of the equivalentfocal length f:

TABLE 12 Thickness d Index 0! Component Element Radil and Spacing:Refraction n R1=+1.96f I LI 111 =0.11f i=1. 50

R1=+0.6Of

sm =0A6! R2, =+1.l5f LII. d2. =0.27f 7n.=l.69

R:,=0.79f II 82am, =0

Rab =0.79f LIIb lb =0.04f mb=l. 57

R'2b=+2.77f

am =0.005f R: =+O.69f HI Ln: (is ==0.06f m =1. 71

R; =-|-l.18f

as =0.005f R4. =+0.41j LIVn d4. =0.03f ni -1.60

R'4.=+0.24f IV 43': =0

Rib =+0.24f LlVb dis =0.10f ni -1.61

R'4b=+0.30f

34.5 =0.l8f ()1 =0 14] R5- =0 58f Lv. d5. :0 04f ta-1.60 R' .=+0.58f V'95m5b =0 R5b=+0.58f Lv (15 =0.12f n5b=1.59 I

R'5b=0.65f

am =0.005f VI L =+3Jf a o f 1 71 v1 5 .07 m

R's =l.5f

The data of Table 12 incorporate corrections for the third order Seidelregion. Upon the introduction of fine corrections, and with an assumedequivalent focal length fof mm., the data for the lens of Example 3 takeon the form of the following Table 13, the system of which has an imageside intersection distance p' of 88.56743 mm. and a spacing of 123.3 mm.between the front vortex of the first element and the diaphragmposition.

TABLE 13 Thickness d and Index of Re- Abbe Component Element Radll, mm.Spacing 0, mm. fraction 11, Number I R =+196. 4292 I L! d1 =11.12388 m=1. 5038 n -66] Llh d2. =26. 91053 m.=1. 6935 xii-=53. 5

Rn== 78. 71816 H 82a.2b=0

Rn. =78. 71816 Lllb da =3. 707961 mb=1. 5704 rib-51.0

83,3 =0. 463495 R: =+69.35278 III Ln: da =6. 488932 m =1.7130 v1 =53. 9

81.4 =0. 463495 R -|-41.32615 Liv. d4. =3.244466 ma-1.6034 7h=38-oR'4,=+24. 10175 IV 84mb=0 R41, =+24. 10175 lVb (14h =10. 15054 mb=1.6127v|s=58.4

84.5 =18. 2.6171 R5: ==58. 10653 Lv, 11 =3. 707961 7151 1- 6031 vs.=38.0

R's,=+58. 10653 V ssmb=0 Rn. =+58. 10653 Lvt, dsb =12. 05087 mb=1. 5891955-61. 2

R'sb= 64. 61678 85.! =0. 463495 R; =+314. 3887 VI Lvr dc =6. 859728 m=1. 7130 vs -53.9

The surface powers and the surface power sums by elements and componentsof the system of Example 3 as set up in Table 13 are for f=100 mm. and I=l0 dptr. as

follows:

. TABLE 14 2. 564 792 dptr.

+ r 5.805 957 dptr.

a. 8.370 749 dptr. m. 6.048 934 dptr.

daze =+l4. 858 845 dptr.

'z.=+ 8. 809 911 dptr.

or! 5. 555 384 dptr.

dm; 7. 246 104 dptr.

@322; 9. 303 461 dptr.

#1 6.017 069 dptr.

4'14. =+14. 600 924 dptr.

a... =-10. 434 607 dptr.

'4.= -25. 035 531 dptr. rv=-- 5. 319 087 dptr.

4b =+25. 421 395 dptr.

c641: 5. 115 520 dptr.

434b=--20. 305 875 dptr.

5u =10. 379 212 dptr.

(#55 20. 758 424 dptr.

5.=-10. 379 212 dptr.

+ 3 7 d t qSv 1.503 322 dptr.

sb= 10.18 pr.

=+19. 255 102 dptr.

2.267 893 dptr.

v1=+ 7.018 701 dptr.

I claim:

1. A high speed objective lens system comprising, from front to back andin front of the diaphragm position, a first component of negative powerhaving surfaces of unequal curvature and having its rear surface concavetoward the rear, a second component of positive doublet form havingexterior surfaces of unequal curvature and having two elements ofopposite power, a third component of positive meniscus form having itsrear surface concave toward the rear, and a fourth component of negativedoublet form, and, behind the diaphragm position, a rear assembly ofGaussian type including at least two elements, said first componentbeing spaced from the diaphragm position by from 0.8 to 1.8 times theequivalent focal length of the system, the air spaces between saidsecond and third components and between said third and fourth componentshaving the shape of negative lenses with the rear surfaces thereofconcave toward the rear, said air lenses functioning convergently, thepowers o; to 41 respectively of the said first through fourth componentsbeing related to the equivalent total power I of the system as follows:

and the first component being spaced from the second component by adistance of from one third to two thirds of the equivalent focal lengthof the system.

2. An objective lens system according to claim 1 in which the rearassembly includes from front to back fifth and sixth components havingrespectively powers w and related to the equivalent power I of thesystem as follows:

3. An objective lens system according to claim 2 in which the sum 5 ofthe powers of the rear surface of said second component and of the frontsurface of said third component and the sum 1 5 of the powers of therear surface of said third component and of the front surface of saidfourth component lie between 0.55 and 1.10 times the total equivalentpower of the system.

4. An objective system according to claim 2 in which the sums to of thepowers of the surfaces of said six components are related to theequivalent power I of the system substantially as follows:

5. An objective system according to claim 2 in which the sums o to ofthe powers of the surfaces of said and in which the ,front vertex of thefirst component is spaced from the diaphragm position by substantially1.28 times the equivalent focal length f of the system and in which thefirst and second components are spaced by substantially 0.48;.

7. An objective lens system comprising, from front to back nine elementsLI, Ln Ln Lm, LN, LN! L L and L said system having an equivalent focallength f and conforming substantially to the following conditions:

Element Radtl Thlcknessdand Indexot Re- Abbe spacings fractionn Number-rR1 +L7f Lr d1 =0.14f m L I1 67 M ii-48f Rh -+1.2f

Ln. d 0-28f Ilsa-1.69 nit-54 R'ln-0-8f arms-0f Rab 0.8f llb dzb -0.03!nib- 1. 57 rah-'51 R'lb-+2.9f

sm =0.0lf Rs =+0.7f Ln! d| =0.07f m -l.7'1 vs =54 0:.4 =0. 01 j R4; LIV.di- -0.03f m.=l.60 I s-=38 R'4n=+D.25f

hn lb of Rib =-+0.25f LIVb dlb =0. 10f mb=l.61 v4b=59 R4b-+ f s =0.19f b=0.13f R -0.6Df Lv. d5. =0-04f nus-1.60 "6-38 R'r.=-|-0.60f

l5-.sb=0f L a 012 159 61 Vb as m5- viv- RAMP-0.65]

85,. =0.01f L a o 09 1 71 34 v1 l 1 y.

8. An objective lens system comprising, from front to back, nineelements L L L L L L Lva, L and L said system having an equivalent focallength mm. and conforming substantially to the 01- 45 lowing conditions:

Thickness 41 Index of Re- Abbe Element: Radli, mm. and Spacing s,traction 1: Number R =+163.6263 Lx d =14.3006 'm =1. 5038 m 667 01.!=47.6686' R1. =+119.3879 Lu. d =27.6764 mn=1. 6935 via-53.5

an. I 0 Rib 80. 0832 Ln dab I 3.8135 nab-1.5704 rib-51.0

R'g5 I-285. 1391 sm' I 0.4767 R; 71.3269 L111 d; I 6.6736 m =1.7130 v;-53.!)

am I 0. 4767 R4. 42. 6927 L vin I 3. 3368 m.=1.6034 s h-38.0

R'u -l- 24. 7877 Ulldb I 0 Rn, 24.7877 Lrvb 44b 10.0104 m ==1.6127 MbSS-fl R'ib -l- 31.0322

.91.; 18. 7814 br =12.7814 Rs. 59. 7606 Lv. (is. I 3.8135 mal. 6031 r5|38.0

R'h -i- 59. 7606 In-5b 0 R 59. 7606 Lv dtb 12. 3938 nab-1. 5591 rib-61.2

Rss 64. 6532 am 0.4767 L R. =+328.9132 d 8 9617 1 30 v l I m I .71 n53.9

9. An objective lens system comprising, item front length I andconforming substantially to the following to back nine elements L L L LL L conditions: L L and L said system having an equivalent focal ElementRadil Thlcknessdand Index 0130- Abbe Spadngs fractions Number:

R1 -+1.6703f 14.. R, H.610 d1 -0-1416 01-1-5038 n-MJ 1., -o.41211f 12,.-+1.1s2s! Lm. ap s dz. -0.27414f in. 1.0 35 rue-53.6

- mes-0 (cemented) Ian. a -o 0am! m-l m4 -s1.o Iva-+2.82! m m -0.oo4721Lin a -o.oes1o; -1 mo -sa.o

""""""" -+1 2553j n n as. -0.00472j IllV a. woman in -1 sou -aa.o

Run-+0.24; o M 14 -+o'mf' di 0.13:1 1s 68.

vs Rub-+0.30", b y I I mb-- 2' m- 24' we; K Bu -0. 50101 d V0- n h fimmjIn IO-WIM file-L603]- ll-38.0

nn- -0 00472! nib-1.5801 run-61.2 L H2580, :1 0 08871 1 71 vx R. s I m I0 n li References Cited in the file of this patent UNITED STATES PATENTS2,662,447 Tronnier Dec. 15, 1953 2,780,139 Lange Feb. 5, 1957 2,796,002Klemt June 18, 1957' 2,824,494 Klemt Feb. 25, 1958 2,844,997 Lange July29, 1958

